A. Field of Invention
This invention pertains to the art of methods and apparatuses regarding the manufacture of tires, and more particularly to methods and apparatuses regarding the application of tire tread components directly from an extruder/gear pump into a tire mold.
B. Description of the Related Art
Conventionally, tires are made by first assembling a tire carcass on a flat drum. The drum is then expanded to place the carcass into the required toroidal shape. Separately, a tread is formed, typically using an extruder, and a belt package is made. The belt package is placed over the carcass and the tread is subsequently placed over the belt package. This creates an unvulcanized or “green” tire. The green tire is then placed into a tire mold where internal pressure is used to push the green tire against the mold, forcing the tread into the specific mold pattern. After sufficient time and temperature within the mold, the green tire becomes vulcanized, or cured. While such conventional tire making processes work well for their intended purposes, they have disadvantages.
One disadvantage is related to the well known fact that tires are generally assembled from many separate components. In order to maintain high quality for tires, each of these components must be precisely located and accurately shaped within the completed tire. Maintaining the required shapes and obtaining sufficient accuracy in the positions of the components is extremely difficult in practice because of the readily deformable nature of the unvulcanized material that is used and because of the conventional gross changes in shape which are impressed on the tire during assembly. What is needed, then, is an improved way to position tire components to minimize these disadvantages.